A “cart,” short for cartridge, refers to a pre-filled container used in a vaporizer pen, typically holding a concentrated oil (THC or CBD). The intense, immediate coughing that often follows inhalation from a cart is a common experience for both new and experienced users. This reaction signals that the respiratory system is being aggressively irritated by the inhaled aerosol. Understanding this involves looking closely at the physical properties of the vapor, the chemical composition of the oil, and the user’s inhalation style.
The Cough Reflex: Physical Irritation and Heat
The cough is an automatic protective reflex designed to clear the airways of foreign material or irritants. When inhaling the aerosol from a cart, several physical factors immediately trigger this mechanism. The vapor is often significantly hotter than the air normally breathed, causing a sudden thermal shock to the sensitive lining of the trachea and bronchial tubes.
The ingredients that form the vapor, such as Propylene Glycol (PG) and Vegetable Glycerin (VG), are hygroscopic. This means they actively draw moisture from the surrounding environment. This moisture-pulling effect dries out the delicate tissues of the throat and lungs, leading to a scratchy sensation that the body attempts to alleviate by coughing.
The aerosol is also composed of extremely small, ultrafine particles. These particles are capable of penetrating deeper into the lungs, reaching the pulmonary region. This deep deposition of foreign particulate matter directly stimulates a stronger irritant reaction and the resulting cough response.
Chemical Irritants and Vaping Additives
Beyond the physical properties of the aerosol, the chemical makeup of the oil concentrate plays a substantial role in triggering a cough, particularly when low-quality or unregulated products are used. A primary concern is the presence of unauthorized cutting agents or diluents, substances added to thicken the oil or increase its volume. The most recognized of these is Vitamin E Acetate, a sticky substance that, when heated and inhaled, interferes with normal lung function. This substance was strongly linked to the outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI).
Another common source of irritation comes from concentrated terpenes, the natural compounds responsible for flavor and aroma. While harmless in other applications, when concentrated and vaporized, terpenes can become harsh respiratory irritants or break down into toxic byproducts, such as methacrolein, upon heating. Some manufacturers add high amounts of these compounds to thin the viscous cannabis oil.
Other irritants include high concentrations of nicotine in non-cannabis carts, which creates a harsh “throat hit.” Finally, poorly processed products may contain residual solvents, pesticides, or heavy metals that leach from the device hardware. All of these become toxic, cough-inducing irritants when vaporized and inhaled.
Vaping Technique and Device Settings
The way a person inhales and the settings on their device significantly influence the intensity of the cough. Taking an overly deep, prolonged, or forceful inhale can overwhelm the airways with a large volume of dense, hot vapor, instantly triggering a violent cough reflex. This is particularly true when using a direct-to-lung (DTL) inhalation technique, which is common with many cart devices.
The temperature setting of the vaporizer battery is another element. Using a device on a high voltage or wattage setting can cause the oil to overheat, producing a harsher, burnt-tasting vapor known as a “dry hit.” This overheated vapor is far more irritating to the respiratory tract than vapor produced at a lower, controlled temperature. Poor device maintenance or overly tight airflow settings can also concentrate the heat and vapor, exacerbating the irritation and the resulting cough.
When Coughing Signals a Deeper Issue
While an initial cough is a common reaction to a new form of inhalation, persistent or worsening coughing may signal a deeper underlying health concern. If the coughing is painful, is accompanied by shortness of breath, chest pain, or fever, it moves beyond simple irritation and could indicate a serious respiratory injury. This constellation of symptoms is characteristic of conditions like chemical pneumonitis or the previously mentioned EVALI, which causes widespread inflammation and damage to the lungs.
Vaping can also aggravate existing, undiagnosed respiratory conditions, such as asthma or chronic bronchitis, causing a cough that is more severe or persistent than expected. If coughing does not subside after adjusting technique and product, or if it progresses to include other respiratory symptoms, it is important to stop use and seek consultation with a physician.